Piston for an internal combustion motor



ug. 24, 1937. E Q LONG 2,090,799

RIsToN FOR AN INTRRNAlJ OONBU'STION MOTOR Filed Aug. 22, 1932 Patented Aug. 24, 1937 PATENT OFFICE PISTON FOR AN INTERNAL COMBUSTION MOTOR Elmer C. Long, Grosse Pointe Park, Mich. Application August 22, 1932, Serial No. 629,805 8 Claims. (Cl. 309-13) This invention relates to certain improvements in alum-inum alloy pistons for internal combustion motors and has for its primary object to provide improved take-up means within the skirt for taking up or holding in the piston skirt under thermal conditions thuspreventing overexpansion of the skirt. A

Another object of the invention is in providing a piston having a skirt separated from the 10 head with improved means for supporting the skirt from the head.

A further object of the invention is in providing a piston having a skirt of a pair of opposing sections with improved resilient yieldable 16 means supporting the sections interiorly of the piston.

A still further object of the invention is in providing a piston with a flexible skirt with transversely disposed portions of material diierent from the skirt, which are associated with the interior web structure of 'the piston in 'an improved manner.

Another still further object of the invention is in providing a piston with a exible skirt and 5 improved means co-actable with the skirt for providing a piston skirt capable of operating with less clearance.

Other and further objects will appear in the specification and be specically pointed out in the appended claims, reference being had to the accompanying drawing, exemplifying the invention, -and in which:-

Figure 1 is a transverse vertical section of this improved pistoni4 taken through the thrust sides of the piston.

Figure 2 is a transverse vertical section taken approximately on the line II-II of Fig. 1.

Figure 3 is a horizontal section taken approximately on the line III-III of Fig. 1.

Figure 4 is a horizontal section taken approximately on the line IVIV of Fig. 2.

The accompanying drawing discloses a head I having a depending side wall 2 for the support of packing ring grooves 3 and extending across the head interiorly thereof are a pair of transversely disposed webs 4, the outer ends of said webs, of which there are a pair, joining at their ends with the side wall of the head and depending downwardly at their ends into legs 5, the depending ends of said legs supporting respective pin bosses 6.

The skirt 'I of the piston comprises a pair of Aopposing sections 8 and 9, said sections being Y separated from the head by respective transverse gaps or slots I0 and from each other by 'a longitudinal gap II and the gap I2 on each pin boss side of the skirt which surround or encompass the legs 5 and respective pin bosses 6.

The section 8 of the skirt is on the power A thrust side of the piston and is supported from 5 the head I and the pin bosses 6 by a pair of webs I3 which extend downwardly from the head but are free from engagement with the side wall 2 of the head and areunited in right angular disposition with one of the transverse 'lo webs 4 and its ifelatable legs 5 and pin bosses 6 as shown in Figs. 1 and 3,

The section 9 is on the compression thrust side of the piston, said section 9 being supported from the pin bosses 6 by a pair of right angular 15 formed webs I4, each of which extend from a respective pin boss to the section 9. Each right angular webv I4 is disposed so that the leg I5 of each web I4 will align with a respective web I3 of the skirt section 8 and whereas the other leg I6 oi each web I4 is disposed parallel to re- 20 spective pin bosses 6 and the extending ends of the leg I6, joining with the outer end of respective pin bosses as designated at I1. As shown in Figs. l and 3, the legs I6 of the webs I4 are spaced from the pin bosses 6, and the extending ends 25 of the legs I5 join the section 9.

Pistons of this improved character are preferably die-cast and in: the moldingA and casting operation, metallic straps of less co-eicient of expansion are inserted in the mold in a mannerl 9 so that portions thereof will be embedded in the metal of the piston and become a part of the piston. These straps of which there are two pairs, may be of steel and are disposed in the piston above and below the pin bosses, the upper pair of 35e straps designated as I8 each being located in the mold parallel with the thrust axis of the piston and disposed so as to bein abutment with respective webs I3 and the legs I5 of the webs I4. The 4o straps I8 at their ends are provided with bent portions I9 which are embedded in the wall of respective skirt sections 8 and 9 in outwardly curving directions and said straps on their upper and lower edges, intermediate of their ends be- 5 ing beveled as designated at 20, the lower beveled edge of each strap being embedded at 2l in the inner face of each pin boss and on their upper beveled edges being embedded in lower portions 22 of respective supporting legs of the pin 50 bosses as shown in Figs. 1 and 2.

The pair of straps 23 which are disposed beneath the pin bosses, abut respective webs I3 and I4 and are embedded at their ends in the sections 8 and 9 similar to the upper pair of straps I8, 55

said straps 23 intermediate their ends being beveled on their upper and lower edges 24, the upper beveled edge of each strap 23 being embedded in the overlapping portion 25 of each pin boss and being embedded on their lower beveled edges in the overlapping portions 26 which are formed on depending portions 2'I of respective pin bosses. Reinforcing lugs 28 over and under engage the upper and lower edges of the straps I8 and 23 adjacent their ends.

The skirt section 8 which is on the power thrust side of the piston, it is to be noted, is directly connected to the head by the depending webs I3 which extend to the head and as the webs I3 are disposed at right angle to the pin bosses, the webs I3 are therefore in a direct line of power thrust when the piston is in operation. The webs Il which support the section 9 from the pin bosses, are not directly connected to the head but are connected to the head through the pin bosses and the pin boss supporting legs 5. 'I'herefore the angular connection of the webs Il with the pin bosses by the legs I6 of said webs paralleling the pin bosses provide a resiliently yieldable take-up means between the section 9 and its-connection with the pin bosses 6 and which means is obviously not a rigid connection as is the webs I3 on the opposite side of the piston with respect to the" skirt section 8.

In the operation of a piston of this improved character in the cylinder of an internal combustion motor, after the piston has been previously machined to diameters wherein the skirt '1 which is the guiding or cross head part of the piston is of larger diameter than the head I and of a clearance of approximately .002 or less than is the diameter of the cylinder, on expansion of the piston due to heat by reason of the aluminum alloy of the skirt having a greater co-eicient of expansion than the straps I8 and 23, the growing or enlarging of the skirt diameter across the thrust sides or sections 8 and 9 will be held from overexpansion by said straps preventing spreading of said sections owing to the straps having 5 less expansion growth and the required take-up of the expansion across the thrust sides of the skirt will be permitted by= the inward drawing of the skirt section 9 occasioned by the resilient yieldable connection of the webs I I through the flexible legs I6 of said webs which are fulcrumed at I1 to the ends of respective pin bosses 6.

The inward movement of the skirt section 9 is brought about by said section being tied to the section 8 by the straps I8 and 23, and during the drawing in movement, said straps are permitted to slide in their places of connection with the pin bosses on their beveled edges and as the skirt section 8 is directly connected to the head through the webs I3, the pulling force of the straps I8 and 23 will therefore be from the power thrust side or skirt section 8 in holding or drawing the flexible skirt section 9 inwar Obviously constructional modifications of the device are possible without departing from the spirit of the present invention and therefore it is to be understood that it is not necessary to limit the invention by the terms used in the foregoing description, excepting such as the state of the art may require.v What I claim is:-

1. A piston having a head and a cross-head thrust sides;

structure connected thereto comprising diametrically opposite slipper sections, pin bosses, right angular resiliently yieldable means joining one oi.'4 said sections with the pin bosses, said head having a side wall, and webs free from the head side' wall and joining said other section with the head and the pin bosses.

2. A piston having a head and a cross-head structure connected thereto comprising diametrically opposite skirt sections, pin bosses, resiliently yieldable means joining one of said sections with the pin bosses, rigid webs depending from the head and joining said other section with the pin bosses, and a pair of transverse members joined at their ends with said sections.

3. A piston comprising a head having a skirt and pin bosses, said skirt being exible on one of its thrust sides and having resiliently yieldable right-angular shaped connection with each pin boss, and a pair of transversely disposed members of different material -from the skirt and each abutting a respective right angular shaped connection and joined at their ends with said piston thrust sides.

4. A piston comprising a head having a skirt and pin bosses, said skirt being exible on one of its thrust sides and having resiliently yieldable right angular shaped connection with each pin boss, and a pair of transversely disposed members of different material from the skirt and each abutting a respective right angular shaped connection and joined at their ends with said piston thrust sides, each of said members having slidable connection with a respective pin boss.

5. A piston having a head and a cross-head structure connected thereto comprising diametrically opposite skirt sections, pin bosses, resiliently yieldable means joining one of said sections with the pin bosses, webs depending from the head and joining said other section with the pin bosses, and a pair of transverse members of a material diierent from the skirt sections joined at their ends to said sections and having slidable connection with respective pin bosses.

6. A piston comprising a head, a skirt having opposing thrust sides, pin bosses, integral walls depending from the head and joining the thrust sides of the skirt and the pin bosses, and members of different material from the skirt disposed in paralleling abutment with said walls, said members having their ends embedded in said thrust sides.

7. A piston comprising a head, a skirt having opposing thrust sides, pin bosses, integral walls depending from the head and joining the thrust sides of the skirt and the pin bosses, and members of diierent material from the skirt disposed I in paralleling abutment with the inner ends of the pin bosses and said walls, said members having their ends embedded in said thrust sides.

8. A piston comprising a head, a skirt having opposing separated thrust sides, pin bosses, ilexible connections from the pin bosses to one of the thrust sides and rigid connections from the pin bosses to the other thrust side, and members of diierent material from the skirt disposed in paralleling abutment with said connections, said members having their ends embedded in said ELMER. C. LONG. 

